Hand telephone



I o. WEEBER HAND TELEPHONE Filed Sept. 11, 1925 Patented Oct. '23, 1928.

UNITED STATES mam omca.

orro wnnnnn, or BERLIN, GEBMAItTY, .assreuon. r smmnus a nnnsxn AKTIENGE- snrmscm'r, WERNERWEB; or SIEMENSSTADT, NEAR BERLIN, GERMANY.

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Application filed September 11,1925, Serial No 55,651, and in Germany January 22, 1925.

In the hand telephones known heretofore the cover of the casing formed as anear-piece and in which the microphone and the telephone are located have been either screwed to the-casing or attached thereto by means of a bayonet socket. Thus, the cover .can be freed straight-way or by means of a screw-Y driver, consequently damage can .easily be done to the apparatus contained inside the casing because the parts are very sensitive, and even a slight variation of their position causes considerable e-fl'fect on their mode of operation.

The'invention now aims at making it im- 35 possible,or at least difiicult for unauthorized persons to loose the cover from the casing, this being attained according to the invention by the cover and its casing being connected by locking members arranged in the interior of the casing, these members only-beinghac- I cessible with the ;aid of a special toot w' enables them to be brought out/of then looking position. I V I According to the invention the'locking fastening devices are preferably formed as flat springs. It is of advantage to' use the same springs hich bring about the conductiveconnection from the cap-shaped .telephone :or microphone to the connecting cord of the mstrument.

The invention is also directed to the special formation of these contact springs, of which one presses in an axial direction against the central pole arranged at the base of the case,

the latter pressing against a'stop of the cover,

whilst the other contact spring exerts a pressure on the case from opposite sides in a radial direction.

-The invention n'ow describes more closely in an actual example-which is shown in Fig.

1 in side elevation with the telephone casing in section whilst Fig. 2 represents the open casing in plan with the telephone case removed.

In the example shown the handle 1 together with the casings 2 and 3 are made of one piece of compressed insulating material.

The latter. is. preferably of hard rubber or the hand telephone is given considerable strength as well as a very light weight. The

telephone 4 and also the microphone are both f formed as cylindrical units, but the drawing only shows the telephone 4. The units are loosely arranged in the casings 2 and 3 and phenol composition because, when this is used, L

have their top portions lying against a stop 5 of the cover 6 or 7.. The conductive connection from the case orfrom the central, outwardly directed pole, to the cord (not shown) takes place over the contact springs 8 and 9 at the bottom of the casings 2 and 3. One contact spring 8 has several arms 10 and 11 bent U shaped, two of these arms 11 having their bent end's' pressing from opposite sides in a radial direction against the case 4, thus forming a contact with the case of the microphone which is constructed. as a pole. The other two arms 10 are provided with catches 12 which are normally tensioned against the inner edge of the-covers 6 and 7 which are preferably of insulating material. In this manner the covers are secured to their casings.

The contact spring 8 is only attached to the base of its casing by means of a screw '13. In order toprevent a turning of the spring 8 openin 14 are provided in the rim of the casing, t e bent portions of the arms '10 and 11 fitting in these. The other contact spring-'9 of the casings 2 and 3 is arranged transverse to the spring'8 and has its slotted, upwardly bent end 15 lying in an axial direction against the central pole 16 which is located at the base of the microphone unit. The units are thus firmly pressed against an annular boss 5 on the inner wall of the closing cover 6 or- 7. In this manner the airspace between the diaphragms of the 'units and the closing covers is restricted laterally on and underneath the case, hence sound waves cannot be absorbed by this space and weaken the efiects of the apparatus.

In the embodiment shown four arms are provided on the contact spring, two of them making contact with the case's, whilst the others are used for holding the cover. The arrangementv can of course be so made by suitably shaping the spring 8 that the same arms serve for both"purposes. 'As'will be seen the arrangement describedallows the covers to be placed onthe casings without the 190 use of a special tool. If, however, the covers' are to e removed from thecasings',it is necessary tolift the catches 12 of the spring 8 from the inner rim of the covers. For this purpose openings. 17 are provided in the cov- 1051 ers at opposite points and "serve-for the insertion' of two ends of a special tool, prefer ably made of a. wire strip'."- The cov'er is now rotated by means of the inserted tool so that the openings 17, come. tolie' opposite the catches 12 and the spring 8, whereupon the catches can be pressed inward-s by means. of the wire ends of the tool and ,the cover can iioff-said unit and additional means be moved Without further difliculty.

What is claimed is: 1. In a hand telephone, a receiver unit having terminals, a casing for receiving said unit, a cover for said casing to hold said unit 1n place,-an element fastened to saldwaslng,

means projecting from said element for making electrical contact with one terminal projecting from said element for holding said cover in l L place, said cover being held in place only by said additional means.

2. In a hand telephone, a receiver caslng, a receiver unit, a cover for said casing engaging said unit to hold it in place in the casing, a conductive element secured to the face of the casing and having a pluralityof arms extending upward therefrom, certain of said arms engaging the outer wall of said unit to form an electrical contact therewith and other of said arms having means asso ciated therewith for locking said cover in place.

3. In a hand telephone set, a casing carrying conductive elements, a unit for said casmg having terminals engaging said elements when the unlt 1s placed in sald caslng, a cover for said casing, means on said cover cooperating with one of said conductive elements to hold the cover in place, and additional means on said cover cooperating with another element to hold said unit in place.

--4. In a hand telephone, a casing for receiving a'receiver unit, a conductive element having extensions and secured to the base of said casing by a single screw, projections'extend' ing from the inner periphery of said casing to prevent rotary movement of said element, a cover for said casing and unit, said extensions of said conductive element and said cover cooperating .to hold said casing,unit and cover together.

5, In a hand telephone, atelephone unit,

a casing, a cover for said casing engaging unit to form an electrical contact therewith and to hold said unit tensioned against said cover. g

In witness whereof,"I hereunto subscribe my name this 20th day of August, A. D. 1925.

' OTTO WEE-BER. 

